mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-06-01 12:41:35 +00:00
chiptune_player: optimize and comment
This commit is contained in:
Vince Weaver
parent
b6e4b5ac8c
commit
d39d531d98
|
|
@ -207,7 +207,7 @@ forever_loop:
|
|||
; Then it sets up the stack like an interrupt and calls 0x3fe
|
||||
|
||||
interrupt_handler:
|
||||
pha ; save A
|
||||
pha ; save A ; 3
|
||||
; tya
|
||||
; pha
|
||||
; txa
|
||||
|
|
@ -216,125 +216,132 @@ interrupt_handler:
|
|||
|
||||
; inc $0404 ; debug
|
||||
|
||||
bit $C404 ; can clear 6522 interrupt by reading T1C-L
|
||||
bit $C404 ; clear 6522 interrupt by reading T1C-L ; 4
|
||||
|
||||
|
||||
;============
|
||||
; 7
|
||||
;=====================
|
||||
; Update time counter
|
||||
;=====================
|
||||
|
||||
inc FRAME_COUNT
|
||||
lda FRAME_COUNT
|
||||
cmp #50
|
||||
bne frame_good
|
||||
inc FRAME_COUNT ; 5
|
||||
lda FRAME_COUNT ; 3
|
||||
cmp #50 ; 3
|
||||
bne frame_good ; 3/2nt
|
||||
|
||||
lda #$0
|
||||
sta FRAME_COUNT
|
||||
lda #$0 ; 2
|
||||
sta FRAME_COUNT ; 3
|
||||
|
||||
update_second_ones:
|
||||
inc $7d0+17
|
||||
inc $bd0+17
|
||||
lda $bd0+17
|
||||
cmp #$ba ; one past '9'
|
||||
bne frame_good
|
||||
lda #'0'+$80
|
||||
sta $7d0+17
|
||||
sta $bd0+17
|
||||
inc $7d0+17 ; 6
|
||||
inc $bd0+17 ; 6
|
||||
lda $bd0+17 ; 4
|
||||
cmp #$ba ; one past '9' ; 2
|
||||
bne frame_good ; 3/2nt
|
||||
lda #'0'+$80 ; 2
|
||||
sta $7d0+17 ; 4
|
||||
sta $bd0+17 ; 4
|
||||
update_second_tens:
|
||||
inc $7d0+16
|
||||
inc $bd0+16
|
||||
lda $bd0+16
|
||||
cmp #$b6 ; 6
|
||||
bne frame_good
|
||||
lda #'0'+$80
|
||||
sta $7d0+16
|
||||
sta $bd0+16
|
||||
inc $7d0+16 ; 6
|
||||
inc $bd0+16 ; 6
|
||||
lda $bd0+16 ; 4
|
||||
cmp #$b6 ; 6 (for 60 seconds) ; 2
|
||||
bne frame_good ; 3/2nt
|
||||
lda #'0'+$80 ; 2
|
||||
sta $7d0+16 ; 4
|
||||
sta $bd0+16 ; 4
|
||||
update_minutes:
|
||||
inc $7d0+14
|
||||
inc $bd0+14
|
||||
; we don't handle > 9:59 songs yet
|
||||
inc $7d0+14 ; 6
|
||||
inc $bd0+14 ; 6
|
||||
; we don't handle > 9:59 songs yet
|
||||
|
||||
;=============
|
||||
; 90 worst
|
||||
|
||||
frame_good:
|
||||
|
||||
ldy MB_FRAME_DIFF
|
||||
ldy MB_FRAME_DIFF ; get chunk offset ; 3
|
||||
|
||||
ldx #0
|
||||
ldx #0 ; set up reg count ; 2
|
||||
|
||||
;=============
|
||||
; 5
|
||||
|
||||
mb_write_loop:
|
||||
lda (INL),y
|
||||
lda (INL),y ; load register value ; 5
|
||||
|
||||
cpx #1
|
||||
bne mb_not_one
|
||||
cmp #$ff ; if ff, done song
|
||||
bne mb_not_one
|
||||
; if REG==1 and high bit set
|
||||
; then end of song
|
||||
|
||||
lda #1
|
||||
sta DONE_PLAYING
|
||||
jmp done_interrupt
|
||||
bpl mb_not_done ; 3/2nt
|
||||
cpx #1 ; 2
|
||||
bne mb_not_done ; 3/2nt
|
||||
|
||||
mb_not_one:
|
||||
cpx #13
|
||||
bne mb_not_13
|
||||
cmp #$ff
|
||||
beq skip_r13
|
||||
lda #1 ; set done playing ; 2
|
||||
sta DONE_PLAYING ; 3
|
||||
jmp done_interrupt ; 3
|
||||
|
||||
mb_not_done:
|
||||
|
||||
; special case R13. If it is 0xff, then don't update
|
||||
; otherwise might spuriously reset the envelope settings
|
||||
|
||||
cpx #13 ; 2
|
||||
bne mb_not_13 ; 3/2nt
|
||||
cmp #$ff ; 2
|
||||
beq skip_r13 ; 3/2nt
|
||||
|
||||
mb_not_13:
|
||||
sta MB_VALUE
|
||||
sta MB_VALUE ; 3
|
||||
|
||||
cpx #8
|
||||
bne mb_not_8
|
||||
and #$f
|
||||
sta A_VOLUME
|
||||
mb_not_8:
|
||||
cpx #9
|
||||
bne mb_not_9
|
||||
and #$f
|
||||
sta B_VOLUME
|
||||
mb_not_9:
|
||||
cpx #10
|
||||
bne mb_not_10
|
||||
and #$f
|
||||
sta C_VOLUME
|
||||
mb_not_10:
|
||||
; INLINE?
|
||||
jsr write_ay_both ; assume 3 channel (not six)
|
||||
; so write same to both left/write
|
||||
clc
|
||||
lda INH
|
||||
adc #CHUNKSIZE
|
||||
sta INH
|
||||
; always write out all to zero page
|
||||
; we mostly care about vola/volb/volc so this wastes 11 bytes of RAM
|
||||
; code is simpler, and save on three cmp/branches per loop
|
||||
|
||||
inx
|
||||
cpx #14
|
||||
bmi mb_write_loop
|
||||
and #$f ; 2
|
||||
sta REGISTER_DUMP,X ; 4
|
||||
|
||||
; INLINE this?
|
||||
jsr write_ay_both ; assume 3 channel (not six) ; 6
|
||||
; so write same to both
|
||||
; left/right
|
||||
|
||||
clc ; point to next interleaved ; 2
|
||||
lda INH ; page by adding $300 ; 3
|
||||
adc #CHUNKSIZE ; 2
|
||||
sta INH ; 3
|
||||
|
||||
inx ; point to next register ; 2
|
||||
cpx #14 ; if 14 we're done ; 2
|
||||
bmi mb_write_loop ; otherwise, loop ; 3/2nt
|
||||
|
||||
skip_r13:
|
||||
lda MB_CHUNK
|
||||
clc
|
||||
adc #>CHUNK_BUFFER
|
||||
sta INH
|
||||
lda MB_CHUNK ; reset input pointer ; 3
|
||||
clc ; to the beginning ; 2
|
||||
adc #>CHUNK_BUFFER ; in proper chunk (1 of 3) ; 2
|
||||
sta INH ; 3
|
||||
|
||||
inc MB_FRAME_DIFF
|
||||
bne done_interrupt
|
||||
inc MB_FRAME_DIFF ; increment offset ; 5
|
||||
bne done_interrupt ; if not zero, done ; 3/2nt
|
||||
wraparound:
|
||||
|
||||
inc MB_CHUNK
|
||||
lda MB_CHUNK
|
||||
cmp #CHUNKSIZE
|
||||
bne chunk_good
|
||||
lda #0
|
||||
sta MB_CHUNK
|
||||
inc MB_CHUNK ; go to next chunk ; 5
|
||||
lda MB_CHUNK ; 3
|
||||
cmp #CHUNKSIZE ; have we reached end? ; 2
|
||||
bne chunk_good ; 3/2nt
|
||||
lda #0 ; if so reset ; 2
|
||||
sta MB_CHUNK ; 3
|
||||
|
||||
jsr next_subsong
|
||||
; can't tail call as need to restore stack and rti
|
||||
jsr next_subsong ; and decompress next ; 6
|
||||
|
||||
chunk_good:
|
||||
|
||||
done_interrupt:
|
||||
pla
|
||||
; tax
|
||||
; pla
|
||||
; tay
|
||||
; pla
|
||||
rti
|
||||
pla ; restore a ; 4
|
||||
|
||||
rti ; 6
|
||||
|
||||
|
||||
;=================
|
||||
|
|
@ -493,11 +500,13 @@ bloop22:
|
|||
; filenames
|
||||
;==========
|
||||
krw_file:
|
||||
.asciiz "INTRO2.KRW"
|
||||
.asciiz "CRMOROS.KRW"
|
||||
.asciiz "CHRISTMAS.KRW"
|
||||
.asciiz "CAMOUFLAGE.KRW"
|
||||
.asciiz "FIGHTING.KRW"
|
||||
.asciiz "UNIVERSE.KRW"
|
||||
.asciiz "INTRO2.KRW"
|
||||
|
||||
.asciiz "TECHNO.KRW"
|
||||
|
||||
;=========
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user